Direct C−H Arylation Meets Perovskite Solar Cells: Tin‐Free Synthesis Shortcut to High‐Performance Hole‐Transporting Materials

In contrast to the traditional multistep synthesis, we demonstrate herein a two‐step synthesis shortcut to triphenylamine‐based hole‐transporting materials (HTMs) through sequential direct C−H arylations. These hole‐transporting molecules are fabricated in perovskite‐based solar cells (PSCs) that exhibit promising efficiencies up to 17.69 %, which is comparable to PSCs utilizing commercially available 2,2′,7,7′‐tetrakis[N,N‐di(4‐methoxyphenyl)amino]‐9,9′‐spirobifluorene (spiro‐OMeTAD) as the HTM. This is the first report describing the use of step‐saving C−H activations/arylations in the facile synthesis of small‐molecule HTMs for perovskite solar cells. The key that fits: Direct C−H activations/arylations are, for the first time, used as key transformations to access star‐shaped hole‐transporting materials (HTMs). These molecules are fabricated in perovskite‐based solar devices that exhibit power conversion efficiencies (PCEs) up to 17.7 %.